Akademik Veri Yönetim Sistemi
JOURNAL OF THE FACULTY OF ENGINEERING AND ARCHITECTURE OF GAZI UNIVERSITY, cilt.27, sa.4, ss.807-812, 2012 (SCI-Expanded)
In this study; Equal Channel Angular Pressing (ECAP) process for 7075 aluminum alloy were succesfully carried out up to 14 passes at 200 degrees C and at pressing speed of 2 mms(-1) by using Route C. After ECAP processes, the specimens were characterized by Transmission Electron Microscope (TEM), hardness and macrostructural investigations. Macrostructural investigations showed that the plastic deformation in the ECAPed specimens occurred from edge to the centre, clock wise and like whirlpool. In addition, the deformation intensity increased with increasing pass number. The mean grain size of the specimens was effectively decreased with increasing ECAP pass number. That is, while the grain size of unECAPed specimen was 10 mu m, this value was decreased to 300 nm at the 14th pass. At the beginning, while there was a banding tendency in the grains toward deformation direction, homogeneous and equ-axed grains were formed by increasing pass number. Hardness results showed that the hardness values increased up to 4 passes, decreased effectively at 6th pass, again increased 8th pass and after this pass, the hardness was again decreased due to dynamic recrystallization.